> Overnight I received several calls from (200) 222 0000. The caller> left no message. Is this a real telephone number?

No.

> If not what is it?

It's a fake telephone number. (Well, you asked.)

R's,

John

PS: The security for CLID data is very sloppy, and there are all sorts
of ways for callers to provide their own CLID that's different from
the actual calling number. Sometimes it's benign as when a company
provides their own 800 number, sometimes it's not.